1. Field of the Invention
The present invention relates to an alternative voltage stabilizer capable of improving transient response and increasing area of stabilized voltage, and especially to one which uses elements such as on-off transistors, capacitors, inductors etc. to supplement or reduce the voltage input to become a rated voltage, has the characters of low dynamic output impedance, fast response, and good stabilizing ratio of voltage and transient response, as well as broader area of voltage stabilized.
The fast development and advance of industry and commerce renders the supply of electricity power to be insufficient when in need, yet establishing of power plants is too slow to be in help due to the difficulty of land obtaining and various protestation, therefore, insufficiency of power supply often occurs during the peak hours of electricity consuming in summer time or when the consumers are the end-consumers, the supply voltage thus often appears to be unstable in high and low values intermitently. The power supply equipment can only be protected and operate regularly by a power stabilizing device to control the voltage to be at a rated value.
2. Description of the Prior Art
Conventional alternative voltage stabilizers include the following types depending on their ways of controlling:
(1) the motor driven self-coupling transformer types: they can produce stable voltages, but have the defects of large volume, heaviness, and slow responsing speed; PA1 (2) magnetic resonance transformer types: they use the principle of resonance to stabilize voltage, however, they have the defects of high working temperature, big noise, large volume, heaviness and low overload current; PA1 (3) silicon controlled rectifier types: they control the phase angles of power sourses, but have the defects of having notches in their output wave forms, having big harmonic distortion, and large volume as well as heaviness; PA1 (4) saturated magnetic field indution types: they use the saturation characteristic of transformers, and also have the defects of big noise, large volume and heaviness; PA1 (5) jumping or digital types: the output voltages of them are non-linear, and are modulated in a level jumping mode, have inferior voltage stabilizing ratio, slow response, and low reliability; PA1 (6) phase transfer or amplifier types: composed of rectifier and filter circuits, have the defects of low input power, low efficiency, and low acuracy. PA1 (1) inferior responsing speed and transient response: their mechanical response speed is about 10-30 cycles, while about 3-5 cycles for electronic type, and about 1.5 cycles for resonant type, the impedance of the dynamic output of such types is very high, thus render the transient response thereof to be inferior; PA1 (2) narrow area of input voltage: the area for normal electronic type is .+-. 15%, for resonant type is .+-. 20%, their availability is therefore limited; PA1 (3) voltage stabilizing ratio and efficiency: the voltage stabilizing ratio of most of them can be coincident with the standard of 1-3%, however, the impedances of the dynamic working current and dynamic output thereof are very high, so that their efficiency is low, and even they are not able to accept any other load outside, they appear on themselves high temperature state, thus apparently do not suffice the practical requirement. PA1 (4) volume and weight: they generally have the defects of heaviness and large volume.
Summarily, the conventional alternative voltage stabilizers include the defects as follows: